Process of making strontia.



NITED STATES PATENT OFFICE.

PROCESS OF MAKING STRONTIA.

SPECIFICATION formingpart of Letters Patent No. 647,320, dated April 10,1900.

Application filed August 4, 1599. Serial No. 726,191. (No specimens.)

To all whom, it may concern:

Be it known that I, SPENCER BAIRD NEW BERRY, of Sandusky, in the countyof Erie and State of Ohio, have invented a new and Improved Process ofManufacturing Strontia from Strontium Sulfate, of which the following isa full, clear, and exact description.

My invention relates to the manufacture of strontia from strontiumsulfate, and has for its object to provide a method by which thenecessary reaction may be produced economically and with much greaterease than according to the processes now practiced.

Strontium sulfate unmixed with other materials can be decomposed byheat; but the process is slow and uncertain, largely owing to thefusibility of the sulfate at high temperatures. I have found that thedecomposition is greatly facilitated and the fusion prevented by addingto the sulfate a suitable proportion of a difficulty-fusible basicmaterial, such as magnesia or lime, carbonate of magnesia, or carbonateof lime. The proportions may be about one to two parts of thedifiicultly-fusible basic material in three parts of the mixturethat is,say one part of basic material and two parts of sulfate or two parts ofbasic material and one part of sulfate. I desire it to be understood,however, that satisfactory results may be obtained with proportionsdifferent from those stated above.

The mixture above described is heated so as to calcine it, the resultingproduct being a mixture of strontia with magnesia or lime, with perhapsa small proportion of undecomposed strontium sulfate. The reaction whichtakes place is essentially the decomposition of strontium sulfate byheat according to the equation:

SrSo :SrO+S0 this action being facilitated and rendered complete by theaction of the basic material forming part of the mixture.

The calcined product is leached with hot or cold water, by which thestrontia is converted terial is molded into bricks and dried beforecalcining.

It will be understood that from the strontia manufactured according tomy process I may produce strontium hydrate, as above referred to, orother strontium compounds, according to the usual methods.

I desire it to be understood that the strontium sulfate employed by meneed not be a chemically-pure substance; but as a rule I employ mineralstrontium sulfate or celestite. The basic material employed also neednot be a pure substance. As a rule I use common lime, limestone,magnesite, or any commercial form of magnesia. These substances,together with any form of carbonate of lime or of magnesia, aretherefore equivalents of lime and magnesia.

Having thus described my invention, I claim as new and desire-to secureby Letters Patent- 1. The method of manufacturing strontia fromstrontium sulfate, which consists in mixing strontium sulfate with theoxid of an alkaline earth, and calcining the mixture at a hightemperature, substantially as set forth.

2. The method of manufacturing strontia from strontium sulfate, whichconsists in mixing strontium sulfate with lime, and calcining themixture at a high temperature.

SPENCER BAIRD NEWBERRY.

\Vitnesses:

P. B. BEERY, H. E. FRANCIS.

